Precision
key notes :
✅ What is Precision?
- Precision means how exact or detailed a measurement is.
- It shows how close repeated measurements are to each other.
🔍 “Same result again and again!”
📏 Precision vs Accuracy
| Precision 💎 | Accuracy 🎯 |
|---|---|
| Results are close to each other | Result is close to the actual (true) value |
| Consistency | Correctness |
🧪 Example: If you measure 5 times and all values are nearly equal → precise.
If the value is close to the real answer → accurate.
📍 Why is Precision Important?
- Helps in science experiments to get reliable results 🧬
- Used in engineering & technology for correct designs ⚙️
- Needed in medicine & pharmacy to give correct doses 💊
🔢 Precision in Math & Measurements
A measurement with more decimal places or smaller units is more precise.
Example:
- 5 cm → less precise
- 5.23 cm → more precise 🧮
🧠 Tools Affect Precision
- Better tools = better precision ✨
📍 Examples: - A ruler with mm markings is more precise than one with only cm.
- A digital stopwatch is more precise than a sand timer ⏱️
🔄 Precision in Repeated Trials
- Perform measurements multiple times.
- If results are very close, the data is precise 📊
ex: 12.3g, 12.2g, 12.3g ✅ – High precision
12.3g, 10.5g, 13.8g ❌ – Low precision
🧮 Precision in Numbers (Significant Figures)
More significant figures = more precision.
Example:
- 2.5 (2 sig figs)
- 2.503 (4 sig figs → more precise)
💡 Quick Tips to Improve Precision
✔️ Use proper instruments
✔️ Avoid parallax errors
✔️ Measure more than once
✔️ Record values carefully
🌟 Summary
Precision helps us make consistent, reliable, and detailed measurements, which is essential in science, maths, technology, and daily life.
Learn with an example
Which measurement is more precise?
- 43.1 days
- 23 days
43.1 days is measured to the tenth of a day.
23 days is measured to the day.
A tenth of a day is a smaller unit than a day. So, the measurement of 43.1 days is more precise.
Which measurement is more precise?
- 46.48 minutes
- 15.1 minutes
46.48 minutes is measured to the hundredth of a minute.
15.1 minutes is measured to the tenth of a minute.
A hundredth of a minute is a smaller unit than a tenth of a minute. So, the measurement of 46.48 minutes is more precise.
Which measurement is more precise?
- 20.9 minutes
- 2.91 minutes
20.9 minutes is measured to the tenth of a minute.
2.91 minutes is measured to the hundredth of a minute.
A hundredth of a minute is a smaller unit than a tenth of a minute. So, the measurement of 2.91 minutes is more precise.
let’s practice!
